The present invention relates to diagnosing tissue and, more particularly, to a system and method for helping to determine a condition of a patient""s tissue, such as based on thermal images of the patient""s tissue.
Medical thermal imaging is a non-invasive diagnostic technique in which the skin surface temperature is mapped by detecting thermal radiation emitted by the skin surface. There are several clinical uses for thermal imaging. For example, thermal imaging is used to determine the extent of a previously diagnosed injury or condition, to detect an internal condition, such as cancer, or to monitor the healing process of a patient.
One particular use of thermal imaging relates to helping diagnose breast cancer. Cancerous areas have abnormal perfusion, which may result in warmer skin surface temperatures and abnormal response to heating and cooling on the skin surface adjacent or near the cancerous region. Such temperature characteristics may be detected by thermal imaging.
Unlike some other modalities of diagnosis, thermal imaging measures a physiological phenomenon which requires no contact with the body and no exposure to potentially harmful radiation. Conventional mammography, on the other hand, detects and/or measure structural or anatomical lesions through an application of radiation.
One aspect of the present invention provides a system for helping to determine a condition of selected tissue of a patient. The system includes memory which stores a plurality of images of the selected tissue acquired over a time period to define an image set. Each image of the image set includes a plurality of image regions. Each image region has a characteristic that is variable over the time period indicative of a temperature condition of an associated part of the selected tissue. The memory also stores a classifier derived from image sets of previously diagnosed tissue having a known tissue condition. The system also includes a processor operative to determine at least one feature value for at least one image region. The feature value is indicative of at least part of the characteristic of the image region over the time period. The processor is operative to apply the classifier to the at least one feature value to provide an indication of the condition of the part of the selected tissue of the patient associated with the at least one image region.
Another aspect of the present invention provides a system for helping to determine a condition of selected tissue of a patient. The system includes memory which stores thermal images of the selected tissue obtained over an image acquisition time period. The selected tissue has been exposed to a cooling challenge during a substantial part of the image acquisition time period. Each thermal image includes a plurality of image regions corresponding to an associated part of the selected tissue. Each image region has a characteristic that is variable over the image acquisition time period and indicative of a temperature condition of the associated part of the selected tissue. A processor is connected with the memory and is operative to determine at least one feature value for at least one image region over the image acquisition time period, which feature value is indicative of the characteristic of the respective image region over the image acquisition time period. The processor provides an indication of the condition of the part of the selected tissue associated with the at least one image region upon applying a predetermined classifier to the feature value.
Yet another aspect of the present invention provides a method for helping determine a condition of selected tissue of a patient. The method includes acquiring an image set of the selected tissue over an image acquisition time period. The image set includes a plurality of image regions, each image region having a characteristic that is variable over the image acquisition time period. The characteristic also is indicative of a temperature condition of an associated part of the selected tissue. A thermal challenge is applied to the selected tissue during part of the image acquisition time period. The characteristic of at least one image region is modeled to quantify a plurality of features for each characteristic being modeled. Each feature has a value functionally related to the characteristic being modeled. At least one feature is selected for the image region. A classifier is applied to the selected feature to provide an indication of the condition of the part of the selected tissue associated with the image region.
Still another aspect of the present invention provides a method for developing image data for use in helping determine a condition of selected tissue of a patient. The method includes providing thermal image data for a plurality of image sets. Each of the plurality of image sets is obtained over an image acquisition time period for selected tissue. An image region is selected for each of the plurality of image sets, which image region corresponds to a part of the selected tissue having a predetermined tissue condition. Each selected image region has a characteristic that is variable over the image acquisition time period for the corresponding image set. Each characteristic also is indicative of a temperature condition for the part of the selected tissue of the corresponding image set. A plurality of features are determined for each selected image region. Each feature has a value indicative of the characteristic of a respective one of the selected image regions. At least one feature is selected for each selected image region having a common predetermined tissue condition. A classifier is developed to describe a statistical distribution based on the values of each selected feature.